i hit 110 on my druid when the last nether disruptor was up, joined a portal group, 2 hours later i was full 860 (minus 1 trinket/ring), ran LFR got 3 piece tier bonus, managed to get a decent lego (dual determination), bought 3 pieces of 915 gear in the AH (around 50k each), a crafted legendary for 100k, got lucky with a titan forged pvp item from 880 to 905 and im 901 in less than 2 days of play time after hitting 110. the factor holding me back was trinkets (you need to farm nethershards) and relics, but bears are easy, just look for thrash relics (got a 900 out my weekly cache). Gearing is ridiculously easy at the moment for alts and requires basically no time at all.
After the argus patch i'm curious how many more guilds will be progressed in Mythic. the Nether crucible (when its unlocked) is going to provide quite a decent survival/dps increase and itll allow you to skip mechanics here and there. Mistress for example you can already skip a phase 1 tornado if you push her correctly (our best pull on mistress so far is 20%), guilds may only need to deal with 1 moontalon on sisters P2.
Initially when ToS was released sisters was referred to as "the wall" but with everyones ilevel going up 15 or so even guilds that were stuck on krosus in NH are able to get them down (this is good). but now the wall is back with Mistress, and i'm assuming the changes with the Nether Crucible will push the wall to Maiden.